So, I would first say there's a fair amount of SCP articles tagged with 'performance'. Don't get me wrong, there's not so many it can't be done, and I personally love a performance-based SCP object, as I read through all of these earlier in the week. But it is fair to note you have some competition, but also some potential inspiration as to how to do this.

So, there's some issues about your clinical tone where it slips into a more casual tone in places. For example -

Thankfully, SCP-XXXX provides a great deal of its own containment, owing to its status as a disused building.

The 'thankfully' line is too casual for a scientific report. Something like 'Currently, SCP-XXXX is located in a disused building', before going into depth about any further Containment Procedures, because The Foundation would do more, as you've already noted.

by foundation personnel

'by Foundation personnel'.

between the hours of 2:00-5:00AM.

This seems like an odd time to do this - a time that would draw more attention, either from neighbours or people like drunks walking home (who tend, IRL, for some insane reason, to be drawn towards disused buildings and alleyways). Is there a reason this can't be done at a more appropriate time - e.g., between 8 and 9am or 17hrs and 18hrs? The start and close of the 'work day' seems like it would draw less attention.

Any attempted intrusions into the building from non-front entrances are to be halted by foundation agents embedded in the New York City Police Department

This seems a bit too intense for a disused building. All disused buildings I've known IRL have been guarded by private security companies and/or guard dogs, never the police. Making the guards seemingly be the police seems a bit intense for a building you want to keep on the downlow.

Beyond this, there aren't any glaring issues that I can see right now. I think it's a bit unorthodox to describe the SCP-XXXX-# in the way you have done, but it doesn't ruin the rhythm of the piece, so I don't think it's particularly a bad thing on this occasion.

I like the idea, all in all. There are some similar ideas in both the current performance-based SCP objects and other ones, where the person viewing the effect takes on the characteristics of a character or person, but it's certainly interesting enough to keep me reading. Bare in mind I may be a bit biased as I already like this sort of SCP article, and it would be wise to solicit more feedback by PMing other staff members or asking in the IRC chat.